Gun perforator



June 9, 1959 T. o. ALLEN cum PERFORATOR Filed Jan. 18, 1957 Cable ruckei VP I I I I P I I I I IJI I I I I INVENTOR. THOMAS O. ALLEN,

Cable Bracket o.- EY.

United States Patent fifice 2,889,774 Patented June 9, 1959 GUN PERFORA'TOR Thomas '0. Allen, Bellaire, Tex., assignor, by mesne assignments, to Jersey Production Research Company, Tulsa, Okla., a corporation of Delaware Application January 18, 1957, Serial No. 635,041 9 Claims. (Cl. 102-20) The present invention is directed to a gun perforator for well casings. More particularly "the present invention is concerned with a gun perforator for perforating wells without leaving debris in the well. In its more specific aspects the invention is concerned with a gun perforator Which is partially expendable.

The present invention may .be briefly described as a perforator for perforating well casings which is provided with a head member and at least two elongated flexible members attached at their upper ends to the'head memher. A plurality of vertically spaced apart guns are arranged on the flexible member for perforating radially the casing when the guns are fired. Firing means are attached to the guns and are carried by the flexible members for firing the guns. Attached to the lower ends of the flexible members is a cylindrical basket member which is adapted to receive and catch debris released into the well bore on firing the guns. The periphery of the cylindrical basket members is provided with a sealing member which seals the wall of the casing and serves also as a wiping lip. The flexible members have means attached thereto for adjusting tension on the flexible members. Thus, when the guns are disintegrated on firing to form and release debris into the well casing, the basket member prevents the debris from falling into the well casing. Also, the open construction of the perforator of the present invention allows the pressure from 2 the exposed "guns .to be dissipated in all directions and thus prevents a majority of charge debris from entering the perforation. v f The head member is suitably provided with means such as a fishing neck adapted to be attached to a wire line for lowering and raising the perforator in the well casmg.

While the guns are preferably shaped charges, it is contemplated to be within the purview of the present invention to employ bullet guns. The guns are suitably carried on the flexible members or cables radially to perforate the casing at about 120 apart. It is understood, of course, that the guns are also vertically spaced apart on the flexible members. A compression spacing member may suitably be arranged between the guns.

The present invention will be further illustrated and described by reference to the drawing in which:

Fig. 1 is an elevational view partly in section of an embodiment of the present invention;

Fig. 2 is a view taken along the lines 22 of Fig. 1;

Fig. 3 is a perspective view of a modification of the basket member employed in the present invention; and

Fig. 4 is a sectional view of a bullet gun perforator.

Referring now to the drawing and particularly to Fig. 1; numeral 11 designates a firing head having a neck 12 on its upper end for attachment by suitable means to a cable member such as a wire line or to an electric cable. Attached to the firing head 11 by their upper ends are a plurality of flexible supporting members such as cables 13, which have attached to the lower end thereof a gun debris retriever 14, which may be of a cylindrical shape and provided with openings 15 to let fluid pass therethrough. Arranged on the cables 13 vertically spaced apart are a plurality of shaped charges 16. The shaped charges 16 contain a high explosive which causes on detonation with a primacord 20 the formation of jets of metal which serves to pierce the well casing, not shown, into which the gun perforator of the present invention is lowered. The primacord 20 is suitably attached to each of the charges 16 which are, in turn, attached to the cables 13 by clamps 21. Vertically spacing and holding the guns 16 apart are compression type charge support members 22.

The cables 13 are arranged in the device of the present invention to be in tension.

The basket member 14 is suitably provided with a rubber sealing means or wiping lip 23 for sealing with the wall of the casing, not shown. The wiping lip or sealing means 23 allows all of the debris resulting from firing of the guns 16 to be directed into the basket 14 and retrieved from the well.

The basket member 14 is shown with the cables 13 extending through the lower end of the basket 14 and terminating in hex nuts 24. These hex nuts '24 may be used for adjusting tension on the cables 13 by using a suitable torque wrench.

In the embodiment shown in Fig. 3 of the present invention, it will be seen that rather than the basket 14 being provided with perforations 15 that the basket construction is of a metal weave 25, which provides the perforations '15.

Referring now to Fig. 4, it will be seen rather than shaped charges .16 that the guns are provided with gun barrels 39 in which are arranged bullets 31, the gun barrel 3'0 having a firing charge 32 and a detonator 33 and leading to an electrical conductor '34 for firing same. The gun barrels 30 are arranged on the cables 13 as arethe shaped charges shown in Fig. 1.

In lieu of employing cables 13, it is to be understood that other flexible. members may be employed such as wires, chains, ropes, and the like. For example, flexible metal strips may be used for the flexible means.

it is contemplated, when three cables are employed, such as illustrated, thata's many as three primacords may be strapped to the inside of the cables to detonate charges in contact with the individualprimacords. In such an arrangement the charges would be spaced radially so that adjacent perforations would be apart in the casing and each primacord would fire one-third of the total charges in the gun. Tension on the cables may be adjusted at a point near the bottom of the gun or below the junk basket. For adjusting the tension torque wrenches may be employed.

It is contemplated that the junk basket or debris retriever may be constructed from any desirable material, such as cast iron, aluminum, magnesium, and other light or drillable metal. As stated the junk basket or debris retriever may be of wire mesh construction. Also, it is contemplated that the debris retriever, when constructed of a wire mesh construction, may be run into the hole in a collapsed position attached to and forming part of the gun perforator.

The present invention is operated by lowering the gun perforator in the well casing to a selected level. At this point, electrical energy either contained in a battery, not shown, in the firing head, or transmitted through an electrical conductor cable sets off the primacord, where shaped charges are used, and causes firing and detonation of the shaped charges, thus perforating the casing as has been described. After the guns have been fired, the device is retrieved from the casing with the debris from the expendable guns contained in the debris remover.

It is desirable to employ an open construction for a gun perforator in the present invention, since, with the open construction, the pressure from the guns is dissipated in all directions and this prevents the charge debris from entering the resulting perforations. Moreover a gun perforator of the type illustrated herein leaves less debris in the well than the conventional type of gun. Furthermore, the employment of flexible members such as cables or wires as tension support members provides the gun with sufficient flexibility and strength to withstand the shock of the explosion without destruction of the total gun.

The gun perforator of the present invention may be readily constructed out of cable and other material which is available and is of exceedingly light construction. The gun perforator of the present invention is of considerable utility and advantage in that it may be readily run into the well and fired without leaving debris in the well. Furthermore, by virtue of the open construction the present gun perforator does not suffer the disadvantage of leaving or driving material into the perforations.

The nature and objects of the present invention have been completely described and illustrated what I wish to claim as new and useful and secure by Letters Patent is:

1. A gun perforator for perforating well casing which comprises, in combination, a head member, at least two elongated flexible members attached at their upper ends to said head member, a plurality of vertically spaced apart guns arranged on and carried between said flexible members for perforating radially said casing when fired, firing means attached externally to said guns and separate from said flexible members for firing said guns, a cylindrical member attached to the lower ends of said flexible members having an open upper end and a closed lower end, sealing means arranged on the periphery of said cylindrical member for sealing with the wall of the casing, and means attached to the lower ends of said flexible members for adjusting tension on said flexible members, said guns on firing forming and releasing debris into the well casing and said cylindrical member preventing said debris trom falling into the well casing, said flexible members providing the gun perforator with suflicient flexibility and strength to withstand the shock of firing said guns without destruction of the gun perforator.

2. A perforator in accordance with claim 1 in which the head member -is provided with means adapted to be attached to a cable member for lowering and raising said perforator in the well casing.

3. A perforator in accordance with claim 2 in which the cable member is an electric cable.

4. A perforator in accordance with claim 1 in which the guns are shaped charges 5. A perforator in accordance with claim 1 in which the guns are bullet guns.

6. A perforator in accordance with claim 1 in which the guns are arranged on said flexible member for perforating the casing radially degrees apart.

7. A perforator for perforating well casing which comprises, in combination, a head member, at least three elongated flexible members attached at their upper ends to said head member, a plurality of vertically spaced apart shaped charges arranged on and carried between said flexible members for perforating radially said casing when fired, said shaped charges being provided with compression spacing members between the shaped charges, firing means attached externally to said shaped charges and to said head member for firing said guns, said firing means being separate from said flexible members, a cylindrical basket member attached to the lower end of said flexible members, sealing means arranged on the periphery of said basket member for sealing with the wall of the casing, a means attached to the lower ends of the flexible members for adjusting tension on said flexible members, said shaped charges being disintegrated on firing to form and release debris into the well casing and said basket member preventing said debris from falling into the well casing, said flexible members providing the perforator with sufficient flexibility and strength to withstand destruction of the perforator.

8. A perforator in accordance with claim 7 in which the flexible members are cables.

9. A perforator in accordance with claim 7 in which the sealing means is a Wiping lip arranged on the upper end of said basket member for sealing and wiping with the wall of the casing.

References Cited in the file of this patent UNITED STATES PATENTS 2,344,778 Keplinger Mar. 21, 1944 2,616,370 Foster Nov. 4, 1952 2,657,576 Boykin Nov. 3, 1953 2,708,408 Sweetman May 17, 1955 2,733,657 Bryant et al. Feb. 7, 1956 2,756,677 McCullough July 31, 1956 

